It is not directly over a flame because it depends on the substance you might not want to heat it too much.you never know what could happen
The answer is A I hope it was right
VOLUME= 5cm*10cm*2cm =100cm^3
but density of iron=7.874g/cm^3
mass=7.874g*100 =787.4g
mass of that block = 787.4g
Reactants are formed from a chemical bond with can be broken down by vaporizing
